The Patent Reference 1 discloses an example of an isothermal transportation container for transporting a substance such as cell tissue to keep it warm. The transportation container disclosed in this application has a double structure of an inner container and outer container for transporting a medical tool for cell tissue around a room temperature. The inner container is provided with a function for cushioning heat accumulation and heat transfer, and the outer container is provided with an insulating function. This structure allows the transportation at around room temperatures.
[Patent Reference 1]
Japanese Patent Laid-Open No. 2004-217290
The above-mentioned conventional transportation container for a medical tool can simply and easily maintain the temperature of a subject to be transported to a predetermined temperature range. However, the heat transfer in the transportation container is restrained, so that there is a fear of the temperature distribution in the transportation container being extremely non-uniform. For example, if the heat dissipation amount from the bottom face of the transportation container is excessively great, the temperature at the bottom side lowers, resulting in that the temperature of the thermal storage medium at the bottom side lowers at an early stage. In this case, even if a thermal storage medium having sufficient heat storage amount is provided on the side of the upper face considering the heat dissipation from the bottom side, it is difficult to transmit the heat storage amount to the heat dissipating section due to the insulating function, so that the amount of heat cannot effectively be utilized. The temperature of the subject to be transported lowers from the bottom side.
When plural transported articles are transported, the heat transfer among the respective transported article is difficult, with the result that the temperature of each transported article varies. As a result, the subject to be transported that cannot be kept within a desired temperature range might be generated. In the case where an open-air temperature is low, or in the case where the time taken for the transportation is long, the amount of heat dissipation increases. Therefore, the heat storage amount should be increased for implementing the heat dissipation. However, the added thermal storage medium might not effectively be utilized due to the insulating function.